Passive entry passive start (PEPS) systems include a portable remote control unit and a base station. The remote control unit, such as a key fob (“fob”), is carried by a user. The base station is at a target device such as a vehicle. The fob and the base station wirelessly communicate with one another for remotely controlling the vehicle.
Passive entry functions provided by a vehicular PEPS system include automatically unlocking vehicle doors when a fob (which will be assumed to be authorized for discussion purposes) is detected in close proximity to the vehicle. The PEPS system should detect that the fob is in close proximity to the vehicle before unlocking the vehicle doors. Otherwise, an unauthorized user may be able to unlock the vehicle whenever the fob is within the general vicinity of the vehicle.
Passive start functions provided by a vehicular PEPS system include automatically starting the vehicle upon a user in possession of the fob pressing a start button located near the driver's seat. The PEPS system detects that the fob is located within the vehicle before starting the vehicle. Otherwise, an unauthorized user sitting within the vehicle may be able to start the vehicle whenever the user in possession of the fob is standing near the vehicle.